import { EventEmitter } from "events";
import { Logger } from "winston";
import { IAvailableInstanceGenerators, IAvailableServicesMsg, IAvailableTopicsMsg, ICommunicationInterface, IExternalEventMsg, IRequestTaskMsg, IResponseTaskMsg } from "../types/communication.interface";

/**
 * A Communication Layer for the Dispatchers.
 * Here, only a Events are used.
 *
 * @export
 * @class EventLayer
 * @implements {ICommunicationInterface}
 */
export class EventLayer implements ICommunicationInterface {

  constructor(
    public readonly subscriptionMode: 'individual' | 'generic',
    public readonly resultSharing: 'individual' | 'generic',
    protected _logger?: Logger
  ){

  }

  async emitNewInstanceGeneratorsAvailable(generators: IAvailableInstanceGenerators) {
    this._emitter.emit('generators',generators);
  }

  async onNewInstanceGeneratorsAvailable(cb: (generators: IAvailableInstanceGenerators) => void) {
    this._emitter.on('generators',cb)
  }

  async emitRpcRequest(name: string, request: IRequestTaskMsg){
    this._emitter.emit(name, request);
  }

  async emitRpcResult(name: string, result: IResponseTaskMsg){
    this._emitter.emit(name,result);
  }

  async onRpcResult(name: string, cb: (result: IResponseTaskMsg) => void){
    this._emitter.on(name, cb);
  }

  async offRpcResponse(name: string, cb: (result: IResponseTaskMsg) => void){
    this._emitter.off(name, cb);
  }

  async onRpcRequest(name: string, cb: (data: IRequestTaskMsg) => void){
    this._emitter.on(name, cb);
  }

  async offRpcRequest(name: string, cb: (data: IRequestTaskMsg) => void){
    this._emitter.off(name, cb);
  }

  async emitNewServicesAvailable(services: IAvailableServicesMsg){
    this._emitter.emit('services', services)
  }

  async onNewServicesAvailable(cb: (services: IAvailableServicesMsg) => void) {
    this._emitter.on('services', cb);
  }

  async onBonjour(cb: (dispatcher: string) => void){
    this._emitter.on('bonjour', cb);
  }

  async emitBonjour(dispatcher: string){
    this._emitter.emit('bonjour', dispatcher);
  }

  async emitNewTopicsAvailable(topics: IAvailableTopicsMsg){
    this._emitter.emit('topics',topics)
  }

  async onNewTopicsAvailable(cb: (topics: IAvailableTopicsMsg) => void) {
    this._emitter.on('topics',cb)
  }

  async onEvent(event: string, cb: (data: IExternalEventMsg) => void){
    this._emitter.on('event_'+event, cb);
  }

  async emitEvent(event: string, data: IExternalEventMsg){
    this._emitter.emit('event_'+event, data)
  }
  
  async offEvent(event: string, cb: (data: IExternalEventMsg) => void){
    this._emitter.off('event_'+event, cb);
  }
  protected _emitter = new EventEmitter();
}